|Jupiter is not 'tilting' more than normal|
|Jupiter and Ganymede|
|2012 is a hoax!|
Jupiter's Actual Tilt
Jupiter's axis of rotation is very close to perpendicular to its plane of orbit. It is only tilted by 3.12° (compare this to Earth's tilt of 23.4°). This means that when observing Jupiter, the angle of the cloud bands is very close to the plane of its orbit.
Could Jupiter be tilted?
No, not without an enormous expenditure of energy. Jupiter is more massive than the Earth, and the speed of its rotation is much faster. A Jovian day is only about 10 hours long. This means that there is an enormous amount of angular momentum stored in Jupiter. Review the Rotational Pole Shift page, and try to imagine the amount of force necessary to change the tilt of Jupiter.
What is going on?
As stated above, the angle of the cloud bands on Jupiter is very close to the plane of Jupiter's orbit. This isn't changing. What is changing over the course of a night is the perceived angle of Jupiter's plane of orbit!
If we were to look at Jupiter when it is near the Eastern horizon in the Northern hemisphere, it may look a bit like this.
Hours later, as Jupiter transits the celestial meridian, it may look like this, and then as the morning sun causes Jupiter to fade from view, it may look like this. What's going on? Is the Earth or Jupiter suddenly wagging back and forth like the tail of the dog? No, but you are!
We live on a sphere
Yes, it's true. I apologize to all of the flatlanders out there, but yes, we do in fact live on the surface of a sphere. The sphere is spinning once every 24 hours. Depending on your location on the globe, this could have a few different effects.
If we lived at the North or South pole, then stars and planets would describe an arc in the sky that would lay parallel to the horizon. If we lived at the equator, the stars and planets would swing through an arc that is perpendicular to the horizon. Since most of us live somewhere else, then what we see is that some stars circle the pole, and some stars describe an arc from horizon to horizon.
As you follow Jupiter from its rising through its setting, the direction you are looking in changes. When Jupiter rises you are facing East. When it transits, you are facing South. When it sets you are facing West. This is because you are on the surface of a spinning sphere. If you were to follow Jupiter with an Alt-Az mounted telescope, you would see the angle of the clouds change as Jupiter moves across through the sky. If, on the other hand, you put the scope into an equatorial mount, then the scope would actually follow the direction of the earth's rotation, and Jupiter would not appear to 'tilt' in the successive images.
The effect of Latitude
As we have seen from the above graphics, the position of the observer on the earth changes the angle at which Jupiter appears to be tilted. In fact, if we were to move the observing point closer to the equator, then Jupiter's 'tilt' would appear to increase.
Jupiter is not 'tilted' any more than it has ever been. The amount of energy required to change Jupiter's axis of rotation is huge, and a passing planet (even a 'dwarf star') would not do it. Doomsayers don't consider the fact that we live on the surface of a sphere, and that the angle that solar system bodies appear to tilt changes over the course of the day.